So far there are approximately 0.17 billion patients with diabetes throughout the world, the vast majority of which are the patients with type II (i.e. non-insulin dependent) diabetes. Currently, the antidiabetic drugs used in clinical are primarily metformins, sulfonylureas, insulins, thiazolidinediones, alpha-glucosidase inhibitors, and dipeptidyl peptidase IV inhibitors. These drugs exhibit good therapeutic effects, but lead to safety issues when being administered in long-term, e.g. liver toxicity, and some drugs have problems such as weight gain and the like. Moreover, in many cases, it is difficult to achieve ideal target for blood glucose control even if combined use of drugs is given. Therefore, there is an urgent need for a diabetes drug with a novel action mechanism.
Sodium glucose cotransporter 2 (SGLT2) is a new target discovered in recent years for treating diabetes. SGLT2 is mainly distributed in renal proximal tubule, with the effect of absorbing the glucose in urine and returning them back into the blood. The method that the concentration of glucose in the blood can be lowered provided that SGLT2 is inhibited, has lowered the blood glucose levels in ever different ways. When the function of SGLT2 is blocked, there are more glucoses secreted to urine, which will help the patients with diabetes to maintain normal blood glucose level. Since SGLT2 inhibitors are not involved in the glucose metabolism, this kind of blood glucose lowering drugs are believed to have good safety.
The Chinese patent CN200610093189.9 disclosed a compound with the following structure as a SGLT2 inhibitor:

wherein A is O, S, NH or (CH2)n, and wherein n=0-3.
The Chinese patent CN200380110040.1 disclosed a compound with the following structure as a SGLT2 inhibitor:

wherein A is a covalent bond, O, S, NH or (CH2)n, and wherein n=1-3.
The Chinese patent CN200480006761.2 disclosed a compound with the following structure as a SGLT2 inhibitor:

wherein X is a covalent bond or a lower alkylidene group.
The present invention disclosed a class of phenyl C-glucoside derivatives containing deoxyglucose structures as novel SGLT2 inhibitors, and these inhibitors can be used to prepare drugs for treating diabetes, particularly non-insulin dependent diabetes.